U.S. patent application number 16/829817 was filed with the patent office on 2020-07-16 for techniques for connection setup of mmwave-based v2x communication systems.
The applicant listed for this patent is QUALCOMM Incorporated. Invention is credited to Sudhir Kumar BAGHEL, Kapil GULATI, Libin JIANG, Junyi LI, Tien Viet NGUYEN, Shailesh PATIL, Zhibin WU.
Application Number | 20200229245 16/829817 |
Document ID | 20200229245 / US20200229245 |
Family ID | 66170775 |
Filed Date | 2020-07-16 |
Patent Application | download [pdf] |
United States Patent
Application |
20200229245 |
Kind Code |
A1 |
WU; Zhibin ; et al. |
July 16, 2020 |
TECHNIQUES FOR CONNECTION SETUP OF MMWAVE-BASED V2X COMMUNICATION
SYSTEMS
Abstract
Various aspects described herein relate to techniques for
connection setup procedures in a wireless communication system
(e.g., a vehicle-to-everything (V2X) communication system in
millimeter wave). In an aspect, the method includes identifying
information for V2X communications, and initiating a random access
procedure based on the identified information. The method further
includes identifying one or more random access channel (RACH)
resources based on the information, identifying one or more RACH
response resources based on the one or more RACH resources, and
performing directional communications using at least the one or
more RACH resources or the one or more RACH response resources.
Inventors: |
WU; Zhibin; (Los Altos,
CA) ; BAGHEL; Sudhir Kumar; (Hillsborough, NJ)
; PATIL; Shailesh; (San Diego, CA) ; JIANG;
Libin; (Seattle, WA) ; LI; Junyi; (Chester,
NJ) ; GULATI; Kapil; (Hillsborough, NJ) ;
NGUYEN; Tien Viet; (Bridgewater, NJ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
QUALCOMM Incorporated |
San Diego |
CA |
US |
|
|
Family ID: |
66170775 |
Appl. No.: |
16/829817 |
Filed: |
March 25, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16161397 |
Oct 16, 2018 |
10631343 |
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16829817 |
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62574600 |
Oct 19, 2017 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W 8/005 20130101;
H04W 64/003 20130101; H04W 4/40 20180201; H04W 74/0841 20130101;
H04W 74/0833 20130101; H04J 13/0062 20130101; H04W 84/18
20130101 |
International
Class: |
H04W 74/08 20060101
H04W074/08; H04W 4/40 20060101 H04W004/40; H04J 13/00 20060101
H04J013/00; H04W 8/00 20060101 H04W008/00; H04W 64/00 20060101
H04W064/00 |
Claims
1. A method of wireless communications, comprising: identifying a
resource available for random access for at least
vehicle-to-vehicle (V2V) communications; identifying a response
resource based on the resource; and performing directional V2V
communications using at least the resource, the response resource,
or both.
2. The method of claim 1, further comprising: identifying the
resource, at least in part, by identifying a discovery
resource.
3. The method of claim 2, wherein the identifying the resource
comprises mapping the discovery resource to the resource.
4. The method of claim 2, wherein if the discovery resource
comprises a plurality of discovery resources, the resource
comprises a plurality of resources, and the response resource
comprises a plurality of response resources then: the plurality of
discovery resources out numbers the plurality of resources, and the
plurality of resources out numbers or equals the plurality of
response resources.
5. The method of claim 1, wherein the identifying the response
resources comprises mapping the resource to the response
resource.
6. The method of claim 1, further comprising: identifying a
location of the resource based on V2V communication
information.
7. The method of claim 6, and further comprising: identifying the
V2V communication information, at least in part, in a received
broadcast message.
8. The method of claim 6, wherein the V2V communication information
is predetermined, at least in part, by an initiating user equipment
(UE).
9. The method of claim 1, wherein the resource comprises a random
access channel (RACH) resource used by multiple initiating user
equipments (UEs).
10. The method of claim 1, further comprising: receiving a response
via the response resource, wherein the response comprises at least
a Zadoff-Chu (ZC) sequence identification (ID) and an initiating UE
ID.
11. The method of claim 1, wherein at least a portion of the
directional V2V communications uses a millimeter wave signal.
12. The method of claim 1, wherein, if the directional V2V
communications occurs in two different directions, a respective
Zadoff-Chu (ZC) sequence is used for each direction.
13. The method of claim 1, wherein the performing directional V2V
communications comprises: transmitting a symbol with a Zadoff-Chu
(ZC) sequence, or transmitting a symbol with a ZC sequence with one
or more bits.
14. An apparatus for wireless communications, comprising: a
transceiver; a memory configured to store instructions; and one or
more processors communicatively coupled with the transceiver and
the memory, wherein the one or more processors are configured to
execute the instructions to: identify a resource available for
random access for at least vehicle-to-vehicle (V2V) communications;
identify a response resource based on the resource; and perform
directional V2V communications using at least the resource, the
response resource, or both.
15. The apparatus of claim 14, wherein the one or more processors
is further configured to execute the instructions to: identify the
resource, at least in part, by identifying a discovery
resource.
16. The apparatus of claim 15, wherein the identify the resource
comprises mapping the discovery resource to the resource.
17. The apparatus of claim 15, wherein if the discovery resource
comprises a plurality of discovery resources, the resource
comprises a plurality of resources, and the response resource
comprises a plurality of response resources then: the plurality of
discovery resources out numbers the plurality of resources, and the
plurality of resources out numbers or equals the plurality of
response resources.
18. The apparatus of claim 14, wherein the identify the response
resources comprises mapping the resource to the response
resource.
19. The apparatus of claim 14, wherein the one or more processors
is further configured to execute the instructions to: identify a
location of the resource based on V2V communication
information.
20. The apparatus of claim 19, wherein the one or more processors
is further configured to execute the instructions to: identify the
V2V communication information, at least in part, in a received
broadcast message.
21. The apparatus of claim 19, wherein the V2V communication
information is predetermined, at least in part, by an initiating
user equipment (UE).
22. The apparatus of claim 14, wherein the resource comprises a
random access channel (RACH) resource used by multiple initiating
user equipments (UEs).
23. The apparatus of claim 14, wherein the one or more processors
is further configured to execute the instructions to: receive a
response via the response resource, wherein the response comprises
at least a Zadoff-Chu (ZC) sequence identification (ID) and an
initiating UE ID.
24. The apparatus of claim 14, wherein at least a portion of the
directional V2V communications uses a millimeter wave signal.
25. The apparatus of claim 14, wherein, if the directional V2V
communications occurs in two different directions, a respective
Zadoff-Chu (ZC) sequence is used for each direction.
26. The apparatus of claim 14, wherein the perform directional V2V
communications comprises: transmitting a symbol with a Zadoff-Chu
(ZC) sequence, or transmitting a symbol with a ZC sequence with one
or more bits.
27. An apparatus for wireless communications, comprising: means for
identifying a resource available for random access for at least
vehicle-to-vehicle (V2V) communications; means for identifying a
response resource based on the resource; and means for performing
directional V2V communications using at least the resource, the
response resource, or both.
28. A non-transitory computer-readable medium storing computer code
executable by one or more processors for wireless communications,
comprising computer executable code to: identify a resource
available for random access for at least vehicle-to-vehicle (V2V)
communications; identify a response resource based on the resource;
and perform directional V2V communications using at least the
resource, the response resource, or both.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a Continuation of U.S. patent
application Ser. No. 16/161,397, entitled "TECHNIQUES FOR
CONNECTION SETUP OF MMWAVE-BASED V2X COMMUNICATION SYSTEMS" filed
Oct. 16, 2018, which claims priority to U.S. Provisional
Application Ser. No. 62/574,600 entitled "TECHNIQUES FOR CONNECTION
SETUP OF MMWAVE-BASED V2X COMMUNICATION SYSTEMS" and filed on Oct.
19, 2017, each of which is assigned to the assignee hereof and are
hereby expressly incorporated by reference herein in their
entireties.
BACKGROUND
[0002] Aspects of the present disclosure relate generally to
wireless communication systems, and more particularly, to
techniques for vehicle-to-everything (V2X) communication systems in
millimeter wave (mmWave or mmW).
[0003] Wireless communication systems are widely deployed to
provide various telecommunication services such as telephony,
video, data, messaging, and broadcasts. Typical wireless
communication systems may employ multiple-access technologies
capable of supporting communication with multiple users by sharing
available system resources. These multiple access technologies have
been adopted in various telecommunication standards to provide a
common protocol that enables different wireless devices to
communicate on a municipal, national, regional, and even global
level. An example telecommunication standard is the 4th Generation
(4G), which includes Long Term Evolution (LTE) and/or LTE-Advanced
(LTE-A). In addition, the 5th Generation (5G) New Radio (NR)
communications technology, used in a wide range of spectrum, is
envisaged to expand and support diverse usage scenarios and
applications with respect to current mobile network
generations.
[0004] V2X communications can be used when a vehicle communicates
with one or more entities or devices that may affect the vehicle,
and vice versa. In an example, V2X communication may incorporate a
specific type of communications, such as vehicle-to-vehicle (V2V)
communications. In some examples, mmWave communications in a V2X
communication system may have different features and requirements
compared with conventional communication systems. For example,
omni-directional links may not be available in mmWave band(s)
(e.g., 10 GHz through 100 GHz) because of the path loss. In
omni-directional transmissions, the path loss may scale as
.lamda..sup.2, where .lamda. is the carrier wavelength. In this
case, when a wireless communication system moves from 2.4 GHz to 60
GHz, the path loss will be very high. In some cases, the path loss
may reach 28 dB or larger. As such, mmWave links may be inherently
directional, and the range or coverage of mmWave communications may
depend on the beam width or directivity of a perspective beam being
used. For instance, by using more antenna elements, the beams may
be narrower, and may reach further in distance or cover more areas
compared with using less antenna elements.
[0005] Accordingly, due to the requirements for increased data
rates, higher throughput, and higher system reliability, new
approaches or procedures may be desirable to improve connection
setup and random access procedure (e.g., in a mmWave-based V2X
communication system), and enhance medium access, in order to
satisfy consumer demand and improve user experience in wireless
communications.
SUMMARY
[0006] The following presents a simplified summary of one or more
aspects in order to provide a basic understanding of such aspects.
This summary is not an extensive overview of all contemplated
aspects, and is intended to neither identify key or critical
elements of all aspects nor delineate the scope of any or all
aspects. Its purpose is to present some concepts of one or more
aspects in a simplified form as a prelude to the more detailed
description that is presented later.
[0007] In an aspect, a method related to connection setup and
random access procedure in a wireless communication system (e.g., a
vehicle-to-everything (V2X) communication system) is provided. The
method may include identifying information for V2X communications.
The method may further include initiating a random access procedure
based on the identified information. The method may further include
identifying one or more random access channel (RACH) resources
based on the information. The method may further include
identifying one or more RACH response resources based on the one or
more RACH resources. The method may further include performing
directional communications using at least the one or more RACH
resources or the one or more RACH response resources.
[0008] In another, aspect, an apparatus for wireless communication
is provided. The apparatus may include a transceiver, a memory
configured to store instructions, and one or more processors
communicatively coupled with the transceiver and the memory. The
apparatus may include instructions executable by the one or more
processors to identify information for V2X communications. The
apparatus may further include instructions executable by the one or
more processors to initiate a random access procedure based on the
identified information. The apparatus may further include
instructions executable by the one or more processors to identify
one or more random access channel (RACH) resources based on the
information. The apparatus may further include instructions
executable by the one or more processors to identify one or more
RACH response resources based on the one or more RACH resources.
The apparatus may further include instructions executable by the
one or more processors to perform directional communications using
at least the one or more RACH resources or the one or more RACH
response resources.
[0009] In another aspect, an apparatus for wireless communication
is provided. The apparatus includes means for identifying
information for V2X communications. The apparatus may further
include means for initiating a random access procedure based on the
identified information. The apparatus may further include means for
identifying one or more random access channel (RACH) resources
based on the information. The apparatus may further include means
for identifying one or more RACH response resources based on the
one or more RACH resources. The apparatus may further include means
for performing directional communications using at least the one or
more RACH resources or the one or more RACH response resources.
[0010] In another aspect, a computer-readable medium storing
computer code executable by a processor for wireless
communications. The computer-readable medium may include code to
identify information for V2X communications. The computer-readable
medium may further include code to initiate a random access
procedure based on the identified information. The
computer-readable medium may further include code to identify one
or more random access channel (RACH) resources based on the
information. The computer-readable medium may further include code
to identify one or more RACH response resources based on the one or
more RACH resources. The computer-readable medium may further
include code to perform directional communications using at least
the one or more RACH resources or the one or more RACH response
resources.
[0011] To the accomplishment of the foregoing and related ends, the
one or more aspects comprise the features hereinafter fully
described and particularly pointed out in the claims. The following
description and the annexed drawings set forth in detail certain
illustrative features of the one or more aspects. These features
are indicative, however, of but a few of the various ways in which
the principles of various aspects may be employed, and this
description is intended to include all such aspects and their
equivalents.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] In order to facilitate a fuller understanding of aspects
described herein, reference is now made to the accompanying
drawings, in which like elements are referenced with like numerals.
These drawings should not be construed as limiting the present
disclosure, but are intended to be illustrative only.
[0013] FIG. 1 is a block diagram illustrating an example of a
wireless communication system (e.g., a vehicle-to-everything (V2X)
communication system) including one or more user equipments (UEs)
communicating with at least a target UE to perform connection setup
and random access procedures, according to one or more of the
presently described aspects;
[0014] FIG. 2 includes two examples of beam patterns used in
millimeter wave (mmWave) communications, according to one or more
of the presently described aspects;
[0015] FIG. 3 is a flow chart illustrating an example of an
mmWave-based V2X communication procedure, according to one or more
of the presently described aspects;
[0016] FIG. 4 is an example of a frame structure used for resource
allocations and usage in V2X communications, according to one or
more of the presently described aspects;
[0017] FIG. 5 is an example of random access resource allocations
with resource mapping in V2X communications, according to one or
more of the presently described aspects; and
[0018] FIG. 6 is a flow chart of an example method for connection
setup procedure in V2X communications, according to one or more of
the presently described aspects.
DETAILED DESCRIPTION
[0019] In some wireless communication systems, major design
components may include, for example, broadcast design, connection
setup procedure, and/or unicast traffic scheduling. In an example,
the broadcast design may be used for discovery procedure, which may
be reused for data traffic. In some implementations, when
performing a system-level design, proper techniques being used for
sub-6 GHz operations, and proper schemes to work in a Non
Stand-Alone (NSA) mode (e.g., coexistence with sub-6 GHz) may need
to be considered.
[0020] For V2X or V2V communications, especially in mmWave band(s)
(e.g., 10 GHz-100 GHz), the connection setup procedure may be a
critical step to establish a V2X or V2V communication link after
the directional discovery step. In some aspects, after the
directional discovery step, the interested vehicle (e.g., a first
user equipment (UE)) may initiate a random access process to
communicate with a target vehicle (e.g., a second UE). In some
examples, the discovery may be a one-way discovery, and the target
vehicle may not be aware of the exact location of the interested
vehicle that initiated the random access. As such, the target
vehicle may not know the direction, from which the target vehicle
can receive request(s) from the interested vehicle. In this case,
there are some concerns on how to ensure the communication resource
(e.g., time and frequency) used for the connection setup to be
known to both the interested vehicle and the target vehicle, or how
to solve multiplicity issues when there are multiple vehicles or
UEs all transmitting from the same direction to reach the target
vehicle or UE.
[0021] As such, new or improved approaches for connection setup of
mmWave-based V2X or V2V communications may be desired in order to
enhance physical layer and medium access procedures, as well as
system reliability.
[0022] The detailed description set forth below in connection with
the appended drawings is intended as a description of various
configurations and is not intended to represent the only
configurations in which the concepts described herein may be
practiced. The detailed description includes specific details for
the purpose of providing a thorough understanding of various
concepts. However, it will be apparent to those skilled in the art
that these concepts may be practiced without these specific
details. In some instances, well known components are shown in
block diagram form in order to avoid obscuring such concepts.
[0023] Several aspects of telecommunication systems will now be
presented with reference to various apparatus and methods. These
apparatus and methods will be described in the following detailed
description and illustrated in the accompanying drawings by various
blocks, modules, components, circuits, steps, processes,
algorithms, etc. (collectively referred to as "elements"). These
elements may be implemented using electronic hardware, computer
software, or any combination thereof. Whether such elements are
implemented as hardware or software depends upon the particular
application and design constraints imposed on the overall
system.
[0024] By way of example, an element, or any portion of an element,
or any combination of elements may be implemented with a
"processing system" that includes one or more processors. Examples
of processors include microprocessors, microcontrollers, digital
signal processors (DSPs), field programmable gate arrays (FPGAs),
programmable logic devices (PLDs), state machines, gated logic,
discrete hardware circuits, and other suitable hardware configured
to perform the various functionality described throughout this
disclosure. One or more processors in the processing system may
execute software. Software shall be construed broadly to mean
instructions, instruction sets, code, code segments, program code,
programs, subprograms, software modules, applications, software
applications, software packages, routines, subroutines, objects,
executables, threads of execution, procedures, functions, etc.,
whether referred to as software, firmware, middleware, microcode,
hardware description language, or otherwise.
[0025] Accordingly, in one or more aspects, the functions described
may be implemented in hardware, software, firmware, or any
combination thereof. If implemented in software, the functions may
be stored on or encoded as one or more instructions or code on a
computer-readable medium. Computer-readable media includes computer
storage media. Storage media may be any available media that may be
accessed by a computer. By way of example, and not limitation, such
computer-readable media may comprise RAM, ROM, EEPROM, CD-ROM or
other optical disk storage, magnetic disk storage or other magnetic
storage devices, or any other medium that may be used to carry or
store desired program code in the form of instructions or data
structures and that may be accessed by a computer. Disk and disc,
as used herein, includes compact disc (CD), laser disc, optical
disc, digital versatile disc (DVD), and floppy disk where disks
usually reproduce data magnetically, while discs reproduce data
optically with lasers. Combinations of the above should also be
included within the scope of computer-readable media. In some
aspects, the computer-readable media may be non-transitory or
include a non-transitory computer-readable storage medium.
[0026] Described herein are various aspects related to V2X
communication systems, for example, a V2V communication system. In
particular, the various aspects are related to techniques or
procedures for connection setup of mmWave-based V2X communications.
In some examples, very high throughput links may be established or
utilized between vehicles (e.g., cars) for transporting large
amounts of data (e.g., camera feeds). These high throughput links
(e.g., continuous video streaming between the vehicles) may demand
or use high-data rate mmWave links. In some examples, the view of a
vehicle may be blocked by, for example, another vehicle ahead or
behind the vehicle. In some aspects, mmWave designs in the Fifth
Generation (5G) New Radio (NR) may not be reused or applied to V2X
communications, because, for example, V2X scenarios may need to
work in out-of-coverage cases where cells or gNBs may not be
involved or available. For example, V2X or V2V communications may
be considered as device-to-device (D2D) or ad-hoc communications.
In some examples, discovery may be used as part of the design for
D2D communications such as LTE-direct. In some cases, high-speed
vehicle(s) may be difficult to manage with conventional cell
handoff procedures. As such, new or improved approaches for
connection setup of mmWave-based V2X communications may be
desired.
[0027] In some implementations, two different operation modes may
be used in V2X communications. One operation mode is proactive
mode. In some examples, the proactive mode may maintain highly
directional links between a vehicle and one or more neighbor
vehicles so that data transport may be started promptly, and with
high-data rate(s). In an aspect, the proactive mode may be used to
keep tracking and to refine beams as the vehicle moves. In an
example, the proactive mode may be used when there is no active
data sessions. In some examples, in proactive mode, a vehicle may
actively use discovery to detect or locate other vehicle(s) in
proximity to the vehicle. In some cases, in proactive mode, a
vehicle may mainly use unicast communications.
[0028] In some aspects, the other operation mode, reactive mode,
may be used in V2X communications. In some examples, a vehicle may
not have associated topology maintained. For on-demand traffic, the
vehicle may choose to establish one or more links (e.g., one-time
broadcast) and transport using a directional link (e.g., one of the
established link(s)). In some implementations, depending on the
range requirement and/or traffic or data amounts, the vehicle may
use a link with either a wide beam or a narrow beam. In an example,
the vehicle may release the link after traffic is stopped. In some
aspects, both unicast and broadcast traffic may be utilized. In
some cases, the vehicle may use on-demand discovery to detect
location with interests (e.g., sensor interests).
[0029] In some aspects, after a discovery step, an initiating UE
may perform handshake(s) with a target UE. For example, the
initiating UE may discover or find the target UE from broadcast
signals or beams sent from the target UE, and then the initiating
UE may try to reach the target UE. In another example, the
initiating UE may identify the target UE based on predetermined
information (e.g., information or schemes stored at the initiating
UE). In an example, after discovery, the initiating UE or an
interested node may initiate random access (e.g., via a random
access channel (RACH)) to the target UE. In some aspects, one or
more directional antennas may be used in V2X communications, for
example, for discovery and/or RACH procedure(s). In an
implementation of one-way discovery, the target UE may not know
where the initiating UE is. As a result, the target UE may not know
which direction the target UE should expect to receive a request
from the initiating UE. In this case, in RACH resource, the target
UE may announce or transmit some information in the discovery
phase, and listen to all directions in turn (e.g., in multiple
slots) to check whether there is any RACH message. In some cases,
resource timing between the initiating UE and the target UE may
need to be considered. For example, the initiating UE may need to
know the time when the target UE receives the connection request
sent from the initiating UE.
[0030] In some examples, the initiating UE may use a discovery
and/or a RACH procedure to obtain or identify information for
directional V2X communications. For example, the information may
include the property, characteristic and/or identifier of the
target UE or vehicle, the directivity of a broadcast or discovery
signal, and/or the direction(s) to reach the target UE or
vehicle.
[0031] In some examples, multiplicity among multiple initiating UEs
and the target UE may need to be considered. For example, there may
be multiple UEs transmitting from the same direction trying to
reach the same target UE. In this case, multiple RACH resource
allocations may be applied and the RACH resources may be limited,
and interference among the multiple UEs may need to be considered.
In some examples, a respective transmission (TX) identification
(ID) may be used for each initiating UE, and may be included in
transmitted symbols. In some cases, the target UE may extract the
TX ID to identify a respective initiating UE from multiple
initiating UEs that are transmitting from the same direction and/or
at the same time. In some examples, the target UE may be in the
proximity of one or more initiating UEs.
[0032] In some aspects, RACH resource allocations and procedures
may be based on or associated with discovery that is discussed
above. In an example, one or more RACH resource locations may be
derived based on the content(s) of a discovery message or signal
(e.g., a Discovery Msg) broadcasted by the target UE, with an
algorithm known by one or more UEs, or all UEs. In an aspect,
many-to-one mapping between discovery resources and RACH resources
may be used. In another aspect, one-to-one mapping between RACH
resources and RACH response resources may be utilized. One example
of the resource mapping is shown in FIG. 5. In some cases, the
number of discovery resources may be larger than the number of RACH
resources, and the number of RACH resources may be equal or larger
than the number of RACH response resources.
[0033] In some examples, when RACH procedures or connections have
been setup, collisions may occur in the RACH communications. For
example, a single RACH resource may be used by multiple initiating
UEs. In this case, to reduce or avoid collisions, each transmitting
(TX) vehicle may use an orthogonal sequence (e.g., a Zadoff-Chu
(ZC) sequence used in LTE) and/or different code(s) in transmit
symbol(s), and the receiving (RX) vehicle may detect the existence
of one or more TX vehicles. In an example, the sequence chosen by
the TX vehicle may be indexed, and the index may be linked to a
different "rendezvous" resource(s) for message-based handshake.
[0034] In some aspects, further message exchanges may be applied
between an initiating UE (or vehicle) and a target UE (or vehicle).
For example, beam alignment may be used after initial discovery. In
an aspect, the initiating UE and the target UE may exchange
position information and/or trajectory estimation. In some
examples, a RACH response may contain a ZC-ID and/or the ID of the
initiating UE. In some cases, for each direction, the initiating UE
and/or the target UE may use a different ZC sequence, and/or the
best beam (1, 2, . . . M), where M is the number of beam directions
to be supported by the UE antenna(s). In some examples, RACH
message(s) may contain one or more additional bits (e.g., in
addition to the ZC sequence or preamble) to show the best beam that
may be used by the initiating UE to reach the target UE. In an
aspect, the initiating UE may support one or more beam-sweeping
patterns from the target UE. For example, the target UE may
transmit and/or receive beams in 8 different directions in the
discovery phase. In an aspect, the initiating UE may detect the
target UE in one out of the 8 different directions (e.g., one
direction with the maximum signal strength out of the 8 different
directions). In some cases, the initiating UE may support up to 12
beam directions, and the best beam perceived by the initiating UE
may not be the one of the 8 directions where the target UE is
currently listening or monitoring for RACH request(s).
[0035] In another example, the sender (e.g., the initiating UE or
the target UE) of the RACH message may be configured to use a
comparatively wider beam to increase the chance of the receiver
(e.g., the target UE or the initiating UE) to capture the beam, due
to the potential mobility between the sender and the receiver (or
the initiating UE and target UE). In an aspect, using a wider beam
may reduce signal-to-interference and noise ratio (SINR) of the
signal at the same distance compared with using a narrower beam. In
an example, the sender may be aware that a message or signal itself
can be decoded in a low-SINR environment (e.g., containing less
information bits in the message or signal), and in some cases, the
best beam may still be included in the message, and the receiver
may know the perception of a proper narrow beam that the sender
wants to use to reach the receiver.
[0036] In some aspects, when transmitting a symbol, the initiating
UE and/or the target UE may encode a few bits. For example, the
initiating UE and/or the target UE may use and/or transmit a single
sequence, or a sequence with a few bits. In some examples, the
sequence may be a ZC sequence, and may not have any data
information. In some examples, absolute orthogonality and
information-carrying capability may be considered when performing
multi-user detection. In an aspect, the receiver (at the initiating
UE or the target UE) may detect the existence of a ZC sequence and
obtain the corresponding ZC ID. For example, the receiver may
identify the ZC sequence as one out of a plurality of
pre-configured ZC sequences. In some cases, if there are two or
more different ZC sequences received simultaneously, the receiver
may decode each of the ZC sequences where the different ZC
sequences may be orthogonal. In an implementation, if the chance of
multi-user presence is low (e.g., a single-user case), sending only
the ZC sequence(s) may waste resource(s). In this case, the sender
(at the initiating UE or the target UE) may encode a couple of bits
as additional information (e.g., in addition to a ZC sequence) to
improve information-carrying capability.
[0037] Each of the aspects described above may be performed or
implemented in connection with FIGS. 1-6, which are described in
more detail below.
[0038] Referring to FIG. 1, in an aspect, a wireless communication
system 100 includes at least a UE 12 or UE 14 in communication
coverage of at least a UE 20. In some examples, the UE 12 or UE 14
may be referred to as an initiating UE in a vehicle (or being
attached to the vehicle or being associated with the vehicle), and
the UE 20 may be referred to as a target UE in another vehicle (or
being attached to another vehicle or being associated with the
vehicle). In an aspect, the initiating UE 12 or UE 14 may
communicate with the target UE 20 directly using beamforming. For
example, the initiating UE 12 or UE 14 may communicate with the
target UE 20 via device-to-device or ad-hoc communications. In some
aspects, multiple initiating UEs including the UE 12 and/or UE 14
may be in communication coverage with one or more target UEs,
including the UE 20. In an example, the initiating UE 12 or UE 14
may transmit and/or receive wireless communications (e.g., beams
for discovery or RACH procedure) to and/or from the target UE 20.
For example, the initiating UE 12 or 14 may be actively
communicating with the target UE 20, for example, to perform
connection setup or RACH procedures.
[0039] In some aspects, the UE 12, 14, or 20 may also be referred
to by those skilled in the art (as well as interchangeably herein)
as a vehicle (or inside a vehicle), a mobile station, a subscriber
station, a mobile unit, a subscriber unit, a wireless unit, a
remote unit, a mobile device, a wireless device, a wireless
communications device, a remote device, a mobile subscriber
station, an access terminal, a mobile terminal, a wireless
terminal, a remote terminal, a handset, a terminal, a user agent, a
mobile client, a client, or some other suitable terminology. The UE
12, 14, or 20 may be a cellular phone, a personal digital assistant
(PDA), a wireless modem, a wireless communication device, a
handheld device, a tablet computer, a laptop computer, a cordless
phone, a wireless local loop (WLL) station, a global positioning
system (GPS) device, a multimedia device, a video device, a digital
audio player (e.g., MP3 player), a camera, a game console, a
wearable computing device (e.g., a smart-watch, smart-glasses, a
health or fitness tracker, etc.), an appliance, a sensor, a vehicle
communication system, a medical device, a vending machine, a device
for Internet of Things (IoT), or any other similar functioning
device.
[0040] According to the present aspects, the UE 12, 14, or 20 may
include one or more processors 103 and a memory 130 that may
operate in combination with a communications management component
40. The communications management component 40 may include a
discovery component 42, RACH management component 44, resource
mapping component 46, and/or sequence management component 48.
[0041] In some examples, the communications management component 40
may be configured to perform one or more connection setup or RACH
procedures as discussed herein. In an aspect, the discovery
component 42 may be configured to broadcast or receive one or more
discovery messages. In an aspect, the RACH management component 44
may be configured to perform RACH resource allocations and related
procedures, for example, RACH request or RACH response. In another
aspect, the resource mapping component 46 may be configured to map
the resources among discovery resources, RACH resources, and RACH
response resources. The sequence management component 48 may be
configured to determine or identify the sequence(s) being used in
the resources.
[0042] In some aspects, the communications management component 40
may be communicatively coupled with a transceiver 106, which may
include a receiver 32 for receiving and processing radio frequency
(RF) signals (e.g., broadcast signals, directional beam signals, or
RACH signals), and a transmitter 34 for processing and transmitting
RF signals (e.g., broadcast signals, directional beam signals, or
RACH signals). The processor 103 may be communicatively coupled
with the transceiver 106 and memory 130 via at least one bus
110.
[0043] The receiver 32 may include hardware, firmware, and/or
software code executable by a processor for receiving data, the
code comprising instructions and being stored in a memory (e.g.,
computer-readable medium). The receiver 32 may be, for example, an
RF receiver. In an aspect, the receiver 32 may receive signals
transmitted by the UE 12, UE 14, and/or UE 20. The receiver 32 may
obtain discovery signals and/or measurements of the signals. For
example, the receiver 32 may obtain signal measurements, and may be
communicatively coupled with the processor(s) 103 and assist the
processor(s) 103 to determine signal-to-noise ratio (SNR),
Reference Signal Received Power (RSRP), Reference Signal Received
Quality (RSRQ), Received Signal Strength Indicator (RSSI), etc.
[0044] The transmitter 34 may include hardware, firmware, and/or
software code executable by a processor for transmitting data, the
code comprising instructions and being stored in a memory (e.g.,
computer-readable medium). The transmitter 34 may be, for example,
a RF transmitter.
[0045] In an aspect, the one or more processors 103 may include a
modem 108 that uses one or more modem processors. The various
functions related to the communications management component 40 may
be included in the modem 108 and/or processor(s) 103 and, in an
aspect, may be executed by a single processor, while in other
aspects, different ones of the functions may be executed by a
combination of two or more different processors. For example, in an
aspect, the one or more processors 103 may include any one or any
combination of a modem processor, or baseband processor, or digital
signal processor, or transmit processor, or transceiver processor
associated with the transceiver 106. In particular, the one or more
processors 103 may implement components included in the
communications management component 40, including the discovery
component 42, RACH management component 44, resource mapping
component 46, and/or sequence management component 48.
[0046] The communications management component 40, discovery
component 42, RACH management component 44, resource mapping
component 46, and/or sequence management component 48, may include
hardware, firmware, and/or software code executable by a processor
for performing connection setup, RACH procedures and related
operations in V2X or V2V communications. For example, the hardware
may include, for example, a hardware accelerator, or specialized
processor. In an aspect, the term "component" as used herein may be
one of the parts that make up a system, may be hardware, firmware,
and/or software, and may be divided into other components.
[0047] Moreover, in an aspect, the UE 12 may include an RF front
end (not shown) and the transceiver 106 for receiving and
transmitting radio transmissions, for example, wireless
communications 26. For example, transceiver 106 may transmit or
receive one or more signals. The transceiver 106 may measure a
received pilot signal in order to determine signal quality (e.g.,
based on RSRP, RSRQ, or RSSI) and for providing feedback. For
example, the transceiver 106 may communicate with the modem 108 to
transmit messages generated by the communications management
component 40 and to receive messages and forward them to the
communications management component 40.
[0048] The RF front end may be communicatively coupled with one or
more antennas 102 and may include one or more low-noise amplifiers
(LNAs), one or more switches, one or more power amplifiers (PAs),
and one or more filters for transmitting and receiving RF signals
(e.g., beam signals). In an aspect, the components of the RF front
end may be communicatively coupled with the transceiver 106 (e.g.,
via one or more communication links or buses 110). The transceiver
106 may be communicatively coupled with one or more modems 108
and/or processor 103.
[0049] In an aspect, the LNA may amplify a received signal at a
desired output level. In an aspect, each LNA may have a specified
minimum and maximum gain values. In an aspect, the RF front end may
use one or more switches to select a particular LNA and a specified
gain value based on a desired gain value for a particular
application. In an aspect, the RF front end may provide
measurements (e.g., Ec/Io) and/or applied gain values to the
communications management component 40.
[0050] The one or more PA(s) may be used by the RF front end to
amplify a signal for an RF output at a desired output power level.
In an aspect, each PA may have a specified minimum and maximum gain
values. In an aspect, the RF front end may use one or more switches
to select a particular PA and a specified gain value of the PA
based on a desired gain value for a particular application.
[0051] The one or more filters may be used by the RF front end to
filter a received signal to obtain an input RF signal. Similarly,
in an aspect, for example, a respective filter may be used to
filter an output from a respective PA to produce an output signal
for transmission. In an aspect, each filter may be communicatively
coupled with a specific LNA and/or PA. In an aspect, the RF front
end may use one or more switches to select a transmit or receive
path using a specified filter, LNA, and/or PA, based on a
configuration as specified by the transceiver 106 and/or processor
103.
[0052] The transceiver 106 may be configured to transmit and
receive wireless signals through an antenna 102 via the RF front
end. In an aspect, the transceiver 106 may be tuned to operate at
specified frequencies such that the UE 12 or UE 14 may communicate
with, for example, the UE 20. In an aspect, for example, the modem
108 may configure the transceiver 106 to operate at a specified
frequency and power level based on the UE configuration of the UE
12, UE 14, and/or UE 20, and communication protocol used by the
modem 108.
[0053] In an aspect, the modem 108 may be a multiband-multimode
modem, which may process digital data and communicate with the
transceiver 106 such that the digital data is sent and received
using the transceiver 106. In an aspect, the modem 108 may be
multiband and be configured to support multiple frequency bands for
a specific communications protocol. In an aspect, the modem 108 may
be multi-mode and be configured to support multiple operating
networks and communications protocols. In an aspect, the modem 108
may control one or more components of the UE 12, UE 14, or UE 20
(e.g., RF front end, transceiver 106), to perform connection setup
and RACH procedures in V2X or V2V communications, or enable
transmission and/or reception of signals based on a specified modem
configuration. In an aspect, the modem configuration may be based
on the mode of the modem and the frequency band in use. In another
aspect, the modem configuration may be based on UE configuration
information associated with the UE 12, UE 14, or UE 20.
[0054] In some aspects, the UE 12, UE 14, or UE 20 may further
include memory 130, such as for storing data used herein and/or
local versions of applications or the communications management
component 40 and/or one or more subcomponents of the communications
management component 40 being executed by the processor(s) 103. The
memory 130 may include any type of computer-readable medium usable
by a computer or processor(s) 103, such as random access memory
(RAM), read only memory (ROM), tapes, magnetic discs, optical
discs, volatile memory, non-volatile memory, and any combination
thereof. In an aspect, for example, the memory 130 may be a
computer-readable storage medium that stores one or more
computer-executable codes defining communications management
component 40 and/or one or more of the subcomponents of the
communications management component 40, and/or data associated
therewith, when the UE 12, UE 14, or UE 20 is operating the
processor(s) 103 to execute the communications management component
40 and/or one or more subcomponents of the communications
management component 40. In another aspect, for example, the memory
130 may be a non-transitory computer-readable storage medium.
[0055] Referring to FIG. 2, two examples of beam patterns used in
mmWave communications in accordance with aspects described herein
are presented. In some aspects, mmWave communications, such as the
wireless communications 26 in FIG. 1, may operate at a frequency
band from 10 GHz to 100 GHz. In some examples, mmWave links may be
inherently directional. As shown in beam pattern 200 and beam
pattern 220, the range of mmWave communications (e.g., the wireless
communications 26 in the wireless communication system 100) may
depend on the beam widths or directivity. For example, beam pattern
200 has coarse or wide beams (e.g., number of beam directions=4),
using a small number of antenna elements, the beams may get wider
but the distance is limited. In another example, beam pattern 220
has fine or narrow beams (e.g., the number of beam directions=12),
and by using more antenna elements, the beams may get narrower but
longer distance can be reached compared to the beam pattern 200. In
some cases, the energy consumption or power budget is related to
the beam widths that can be used.
[0056] In some aspects, path loss between a transmitter and a
receiver may not change as a function of frequency, as long as the
effective aperture of the transmitting and receiving antennas does
not change. In some examples, the antenna aperture does reduce in
proportion to the square of the frequency, and the reduction may be
compensated by using higher antenna directivity.
[0057] Referring to FIG. 3, a flow chart illustrating an example of
a mmWave V2X procedure 300 that can be used in, for example, the
wireless communication system 100. In an aspect, the mmWave V2X
procedure 300 may start with a timing synchronization, for example,
via a Global Navigation Satellite System (GNSS) or a Global
Positioning System (GPS). If an upper layer determines there are
potential or existing V2X communications (e.g., sensor sharing), UE
12 or UE 14 may use transmission or reception beam-sweeping (or
both) to detect neighbor V2X UEs in proximity to the UE 12 or UE
14. In an aspect, when discovery of a neighbor vehicle (e.g., a
target UE, or UE 20) in a certain direction as the target is
performed (by initiating UE 12 or UE 14), the initiating UE 12 or
UE 14 may calculate the RACH resources of the neighbor vehicle for
a directional beam, and then send a wide beam with an initial
access request (e.g., RACH-like) to the target vehicle (e.g., UE
20). After sending the initial access request, the initiating UE 12
or UE 14 may listen or monitor for a RX beam for a response in a
designated time slot. In some examples, the initiating UE 12 or UE
14 may receive a RACH response from the target vehicle, e.g., UE
20, to establish a unicast link with at least a Radio Resource
Control (RRC) message over PC5 (a one-to-many communication
interface) or sidelink at the physical layer, and update Medium
Access Control (MAC) schedule with this new unicast link. In some
examples, the initiating UE 12 or UE 14 may identify master or
slave roles for beam tracking or refining, keep link(s) alive, and
measure and/or refine the beam for the link(s). When traffic data
needs to be communicated, the UE 12 and/or UE 14 (or UE 20) may
conduct or perform transmission or reception based on the MAC
schedules. In some cases, when the UE 12 (or UE 14, UE 20) detects
collisions and/or interference, the UE 12 (or UE 14, UE 20) may
update MAC schedule accordingly.
[0058] Referring to FIG. 4, in an aspect, a UE (e.g., UE 12, 14 or
20 in FIG. 1) may allocate or use resources based on a
predetermined frame structure. For example, as shown in FIG. 4, the
UE may use a frame structure 400 for resource allocations or usage.
In some implementations, the UE may use a 5G frame structure as a
basis, for example, with flexible numerology, and/or flexible
Transmission Time Intervals (TTIs). In some examples, around 10% of
the resources may be shared or used for discovery, RACH procedure,
broadcast and slow-loop control, and 90% of the resources may be
used for unicast traffic and associated traffic management
signaling. In some cases, resources may be repeated (e.g., in frame
cycles) as shown in FIG. 4. In an example, a cycle duration may be
ten milliseconds to ten seconds (10 ms-10 s), and may include
common control resources and resources dedicated for traffic and/or
associate data plane control. In an example, the common control
resources may include discovery and/or RACH resources, and the
resources dedicated for traffic may include unicast traffic and/or
broadcast traffic.
[0059] Referring to FIG. 5, in an aspect, an example of a RACH
resource allocation scheme 500 with resource mapping is
illustrated. In an example, one or more RACH resource locations may
be derived (e.g., via arrows 510 and/or 520) based on the
content(s) of a discovery message or signal (e.g., a Discovery Msg)
broadcasted by the target UE, with an algorithm known by one or
more UEs, or all UEs. In an aspect, many-to-one mapping between
discovery resources and RACH resources may be used. For example,
via arrow 510, resource mapping component 46 may be configured to
map one or more discovery resources in the discovery message to one
of the RACH resources. In another aspect, one-to-one mapping
between RACH resources and RACH response resources may be utilized.
For example, via arrow 520, the resource mapping component 46 may
be configured to map each of the RACH resources to one of the RACH
response resources. In some cases, the number of discovery
resources may be larger than the number of RACH resources, and the
number of RACH resources may be equal or larger than the number of
RACH response resources.
[0060] Referring to FIG. 6, in an operational aspect, a UE, such as
UE 12, UE 14, or UE 20 in FIG. 1, may perform one or more aspects
of a method 600 for managing connection setup in a wireless
communication system (e.g., an mmWave-based V2X communication
system). For example, one or more of the processors 103, memory
130, modem 108, transceiver 106, communications management
component 40, discovery component 42, RACH management component 44,
resource mapping component 46, and/or sequence management component
48, may be configured to perform aspects of the method 600.
[0061] In an aspect, at block 602, the method 600 may include
identifying information for V2X communications. In an aspect, for
example, the communications management component 40, e.g., in
conjunction with one or more of the processors 103, memory 130,
modem 108, and/or transceiver 106, may be configured to identify
information for V2X communications. For example, the information
may include one or more discovery resources, RACH resources mapping
information, the property, characteristic and/or identifier of a
target UE, the directivity of a broadcast or discovery signal,
and/or the direction(s) to reach the target UE. In some cases, the
information may be received (e.g., via transceiver 106) in a
broadcast or discovery message, or predetermined by an initiating
UE (e.g., via one or more of the processors 103 at UE 12).
[0062] In an aspect, at block 604, the method 600 may include
initiating a random access procedure based on the identified
information. In an aspect, for example, the communications
management component 40, discovery component 42, RACH management
component 44, e.g., in conjunction with one or more of the
processors 103, memory 130, modem 108, and/or transceiver 106, may
be configured to initiate a RACH procedure based on the identified
information. In an example, the RACH procedure is initiated in
response to receiving a discovery message.
[0063] In another aspect, at block 606, the method 600 may include
identifying one or more RACH resources based on the information. In
an aspect, for example, the communications management component 40,
discovery component 42, RACH management component 44, resource
mapping component 46, e.g., in conjunction with one or more of the
processors 103, memory 130, modem 108, and/or transceiver 106, may
be configured to identify RACH resources based on the identified
information (e.g., in a received discovery message). In some
examples, the resource mapping component 46 may be configured to
map discovery resources in the discovery message to the RACH
resources. In an aspect, the RACH management component 44 and/or
resource mapping component 46 may be configured to identify the
location of each RACH resource based on the identified information
(e.g., in a received discovery message).
[0064] In an aspect, at block 608, the method 600 may include
identifying one or more RACH response resources based on the one or
more RACH resources. In an aspect, for example, the communications
management component 40, RACH management component 44, resource
mapping component 46, e.g., in conjunction with one or more of the
processors 103, memory 130, modem 108, and/or transceiver 106, may
be configured to identify RACH response resources based on the
identified RACH resources at block 606. In some examples, the
resource mapping component 46 may be configured to map each of the
RACH resources to one of the RACH response resources.
[0065] In another aspect, at block 610, the method 600 may include
performing directional communications using at least the one or
more RACH resources or the one or more RACH response resources. In
an aspect, for example, the communications management component 40,
sequence management component 48, e.g., in conjunction with one or
more of the processors 103, memory 130, modem 108, and/or
transceiver 106, may be configured to perform directional
communications using the identified RACH resources at block 606
and/or the identified RACH response resources at block 608. In some
examples, the communications management component 40 and/or
sequence management component 48 may be configured to receive a
RACH response using at least one of the RACH response resources,
and the RACH response comprises at least a Zadoff-Chu (ZC) sequence
identification (ID) and an initiating UE ID.
[0066] For purposes of simplicity of explanation, the methods
discussed herein are shown and described as a series of acts, it is
to be understood and appreciated that the method (and further
methods related thereto) is/are not limited by the order of acts,
as some acts may, in accordance with one or more aspects, occur in
different orders and/or concurrently with other acts from that
shown and described herein. For example, it is to be appreciated
that a method could alternatively be represented as a series of
interrelated states or events, such as in a state diagram.
Moreover, not all illustrated acts may be required to implement a
method in accordance with one or more features described
herein.
[0067] Several aspects of a wireless communication system have been
presented with reference to a V2X or V2V system. As those skilled
in the art will readily appreciate, various aspects described
throughout this disclosure may be extended to other communication
systems (e.g., 5G New Radio (NR)), network architectures and
communication standards.
[0068] By way of example, various aspects may be extended to other
communication systems such as High Speed Downlink Packet Access
(HSDPA), High Speed Uplink Packet Access (HSUPA), High Speed Packet
Access Plus (HSPA+) and TD-CDMA. Various aspects may also be
extended to systems employing Long Term Evolution (LTE) (in FDD,
TDD, or both modes), LTE-Advanced (LTE-A) (in FDD, TDD, or both
modes), CDMA2000, Evolution-Data Optimized (EV-DO), Ultra Mobile
Broadband (UMB), IEEE 602.11 (Wi-Fi), IEEE 602.16 (WiMAX), IEEE
602.20, Ultra-Wideband (UWB), Bluetooth, and/or other suitable
systems. The actual telecommunication standard, network
architecture, and/or communication standard employed will depend on
the specific application and the overall design constraints imposed
on the system.
[0069] It is to be understood that the specific order or hierarchy
of steps in the methods disclosed is an illustration of exemplary
processes. Based upon design preferences, it is understood that the
specific order or hierarchy of steps in the methods may be
rearranged. The accompanying method claims present elements of the
various steps in a sample order, and are not meant to be limited to
the specific order or hierarchy presented unless specifically
recited therein.
[0070] The previous description is provided to enable any person
skilled in the art to practice the various aspects described
herein. Various modifications to these aspects will be readily
apparent to those skilled in the art, and the generic principles
defined herein may be applied to other aspects. Thus, the claims
are not intended to be limited to the aspects shown herein, but is
to be accorded the full scope consistent with the language of the
claims, wherein reference to an element in the singular is not
intended to mean "one and only one" unless specifically so stated,
but rather "one or more." Unless specifically stated otherwise, the
term "some" refers to one or more. A phrase referring to "at least
one of" a list of items refers to any combination of those items,
including single members. As an example, "at least one of: a, b, or
c" is intended to cover: a; b; c; a and b; a and c; b and c; and a,
b and c. Moreover, nothing disclosed herein is intended to be
dedicated to the public regardless of whether such disclosure is
explicitly recited in the claims.
* * * * *